Saturday, February 23, 2019

Adobe has added a cool new geeky feature in the latest release of Lightroom and ACR. These are Classic 8.2, CC 2.2, and ACR 11.2. The feature uses machine learning to analyze and learn from your raw file to eke out the last very bit of detail. For some cameras that have non-Bayer mosaic sensors such as Fuji's X-trans sensors, this is enormously impactful and improves almost every image. However for regular Bayer sensors, you will rarely see any improvement. I estimate that perhaps 1% of my images show any improvement and then you will only see it in humongous prints. The problems manifest in artifacts visible in the standard demosaic and are solved by the enhanced detail feature. For the fall color image below that shows definite improvement when looked at at 1:1, I have a 4 feet high print in my office where you will have a hard time seeing it. So this feature is really for the most extreme pixelpeepers out there. Nevertheless since I am a geek and appreciate the imaging science behind this, I thought I'd show you a few instances where you can expect improvement. These all have to do with the very specific characteristics of Bayer array sensors. A Bayer array sensor as is common in almost every DSLR and also cellphones and compact cameras, has its pixels laid in a way that you have twice as many green sensitive pixels as blue or red. It looks like the below where every square is a single pixel on the sensor and the color indicates different color filters in front of the pixel:

The job of a raw converter is to try and intelligently interpolate between the different pixels to generate a full color image. The existing algorithms for this are not always very smart and even Nikon's own raw converter can generate artifacts under certain circumstances. However Adobe has done something extraordinary and uses artificial intelligence to get around this problem. Also, the above figure immediately tells you that detail that only has blue or red will be prone to artifacts. This is precisely where you might find improvement from this feature. Below is a zoomed in view of an image I found in my library that had these exact issues. These are images from a Nikon D600 which is a 24 MP camera. Remember that yellow is really green and red combined. You should click or tap it to see it bigger:

You can clearly see that in the regular image as well as the image converted using Nikon's own software there are very ugly artifacts around the leaves. The enhanced detail algorithm is able to get around the problems caused by the Bayer mosaic sensor lack of detail in blue and red. To make it more obvious here is the two even more zoomed-in views:

Standard Demosaic

Enhanced Details:

Note that at the scale you are watching this, if you are on a typical desktop computer, it would correspond to a print that is 10 feet high. Again, I want to be clear that enhanced details only matters on ginormous prints. It does not matter for any reasonable size print and definitely not for online images.
Another type of feature where you might see improvement is sharp colored edges against blue skies. Again most visible around red objects. Here is an example from the temple of the sun picture I opened this post with that was taken in Cathedral Valley in Capitol Reef National park at sunrise. A beautiful and not too well known location. Again click/tap for bigger

You can clearly see on the diagonal feature that the old demosaic (right hand side) causes stair stepping artifacts while the enhanced details version (left) has a smooth edge. Again you will only see this in absolutely gigantic prints. What you see me do here is taking pixel peeping to the absolute extreme. Another thing to take into account is that the process of doing an enhanced details creates a new dng file that is about 4x the size of the original file. For the tiny enhancements you might find in a tiny subset of images, it is highly unlikely to be worth it to do this except if you find egregious problems like in the fall leaf image. Even then you would need to print at gigantic sizes.

To conclude this post here is the full version of the leaf image above. You can see that the detail that I used above is tiny. See if you can find where I took the sample.

Saturday, July 8, 2017

Last week I visited hidden Mystic falls which is close to Telluride, Colorado. It is an amazing box canyon waterfall that you have to scramble a bit for to reach. There are many pages on the web that detail how to reach it. The best is probably found here. I rode to the trailhead in my little Subaru without any issue but I might be a lot less careful than most so hiking the last part is not a big deal if you need to especially since the descent to the falls is really quite short. I have three favorite images to share that were taken at different angles and focal lengths.

My favorite is the tighter composition at the end but it does omit some of the context. I am guessing this place is going to be awesome in fall! Lastly as a bonus, here is a 360 degrees panorama of the place. Follow the "view on google maps link to see it in full screen glory and don't forget to look all around!

Thursday, March 2, 2017

I went on a short evening hike with my daughter and thought I would generate a few more immersive panoramas. This time (contrary to the last time I was there! see here and here) it was clear and even warm. This panorama was taken on the lookout point over Golden and Denver. This is right next to my favorite bonsaï-like tree there that you can see here. Make sure to click on the "view on Google maps" link to see it large and to use your mouse (or finger on a mobile device) to look all around.

I also took a panorama at the top in the same spot as I did last time. I was not aware that there was so much of a view up there as it was completely fogged in then. Not so much this time.